Conventional UPnP (universal plug and play) proxy is for allowing an Internet user to find and control in-home UPnP devices at a remote place via the UPnP proxy embedded in a home gateway or a home server. The UPnP proxy provides a unidirectional access and control to the in-home devices from the external Internet, but fails to provide bidirectional access and control between UPnP devices in physically spaced heterogeneous UPnP networks and does not provide steaming services between UPnP A/V devices. Moreover, the UPnP proxy does not allow simultaneous and secure multicasting of contents to UPnP media devices in different UPnP networks.
Interconnection of heterogeneous UPnP networks using JXTA (Juxtapose) protocol is to transmit multimedia data between UPnP media devices based on a relay service, which is the core function of JXTA. However, such interconnection uses multiple unicasts in transmitting contents between the UPnP media devices, which increases a relay peer load and thus causes a transmission delay due to lack of network resources when contents are simultaneously streamed to the UPnP media devices in different UPnP networks.
Multimedia streaming using a virtual media server between UPnP based home networks has been also proposed. However, such multimedia streaming has some disadvantages that a home connector needs to be installed in each home network, setting of the connector for connection between the home networks is performed manually and a dynamic configuration according to movement of users is difficult. Further, since the virtual media server relays streaming data while collecting contents information of other media servers, which results in load concentration.
In order to support mobility of UPnP devices, an SIP (Session Initiation Protocol) based mobility provision has been proposed. However, since each UPnP device needs to support SIP, previously-developed UPnP devices need to be redeveloped to apply such mobility provision thereto. Further, such mobility provision fails to provide simultaneous and secure multicasting of contents to UPnP media devices in different UPnP networks.